This new work started as a collaboration with Arancha Casal and Peter Lee in the Immunology Department at Stanford University. It consists of simulating cellular activity in the Germinal Center, a site in the lymph node responsible for the rapid proliferation and selection of B cells, whose main function is the production of antibodies in response to foreign proteins of bacteria, viruses, and tumor cells. This simulation will involve parameterized probabilistic automata, and our goal is to estimate the values of the parameters to best explain available partial experimental evidence. We hope that this research will contribute to a better understanding of cellular activity in the Germinal Center.